JPH04250156A - Bone joint plate - Google Patents

Abstract

PURPOSE: To provide a plate for osteosynthesis capable of carrying out transplan tation while protecting a bone and a soft part by a controlled method. CONSTITUTION: A plate for osteosynthesis has an upper surface 1, a lower surface 2, a plural, number of holes 3 to receive a bone screw 30 and to make the upper surface 1 and the lower surface 2 communicate with each other, two plate ends 5, 7 and two side part plate walls 9. One plate end 5 is a free end, but the other plate end 7 has an introduction and sight device 20 and a connecting means 8 connected to it free to connect and disconnect from it. It is possible to easily carry out transplantation while inspecting various conditions and protecting the bone and a soft part as much as possible by the plate for osteosynthesis concerning this invention.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an osteosynthesis plate according to the preamble of claim 1.

0002

2. Description of the Related Art When treating bone fractures surgically, the so-called planing technique has become established. The shape and structure of the bone plate will vary depending on the characteristics and anatomy of the bone to be fixed.

[0003] In contrast to so-called intramedullary nail fixation, the aim of plate osteosynthesis is as precise a reduction as possible of the individual bone fragments and optimal stabilization of the fracture. Only when these two factors are achieved can primary union of the fracture be achieved. This will also protect the transplanted tissue from overwork.

[0004] In recent years, a trend has been observed in diaphyseal fractures away from plate osteosynthesis and toward intramedullary nail fixation. There are two reasons above all for this trend. With advances and improvements in x-ray image intensifiers, fractures can be reduced and nailed without direct visual inspection. The second reason is biological treatment. That is, the fracture is no longer incised, which contributes to considerably weakening the circulation disturbance. However, despite initial excitement, the drawbacks of intramedullary nail fixation gradually became apparent. In addition to the medullary canal incision, which is technically demanding and endangers the soft tissue, the central blood circulation of the bone is also continuously destroyed along its entire length.

[0005]

SUMMARY OF THE INVENTION The present invention seeks to provide a remedy in this respect. The object of the present invention is to provide an osteosynthesis plate that can be implanted in a controlled manner while protecting the bones and soft parts as much as possible.

[0006]

SUMMARY OF THE INVENTION To this end, the invention provides an osteosynthesis plate with the features of claim 1 and an introduction and aiming device with the features of claim 8.
ielvorrichtung).

The osteosynthesis plate according to the invention is basically the same as a fixed nail, but the fixed nail is outside the medullary canal. As with intramedullary nailing, the entrance is far away from the fracture site, but unlike with intramedullary nailing, it does not have to be on the longitudinal axis of the bone, so it can be freely selected. After making a very small incision far away from the fracture, a passage corresponding to the plate in dimensions is prepared in the soft tissue up to the bone surface. The osteosynthesis plate according to the invention is constructed like an iron and is pushed from the tip through this passage along the bone surface and onto the fracture. Additional passages must be prepared along the bone depending on the anatomical situation. This passage can basically be prepared without a blade, but in some cases it can also be prepared while being inspected arthroscopically. However, this additional preparation is rarely necessary. Because the osteosynthesis plate according to the invention has the function of bridging fractures due to its length, it does not have to be adapted to the bone, unlike conventional plates. That is, the fracture does not need to be 100% anatomically reduced, and no compressive force is applied to the fracture.

After placing the osteosynthesis plate according to the invention inside the prepared channel, the plate is screwed to the bone. This screwing is performed as follows.

[0009] The guide grip attached to the plate has a guiding function when fitting the plate, as well as a function as an aiming aid when installing a bone screw. For this reason, the holes provided in the guide handle correspond to the screw holes in the plate. Drilling, measuring the required thread length, optionally cutting the thread, and installing the thread are carried out in a suitable manner by means of a guide grip and a soft part piercing.

According to a preferred embodiment of the invention, the hole in the plate is of conical design and preferably has an internal thread. Correspondingly, the screws used to secure the plates have conically terminated heads, preferably with external conical threads. The screws are screwed into the bone through holes in the plate. When the screw is completely screwed in, the conical head of the screw is tensioned in the conical hole of the plate, and this effect is further aided primarily by the thread provided. This tension is important when screws are to be inserted only into the cortex and when the plate is not placed on the bone surface. In this type of threaded joint, the angle between the plate and the screw is fixed. In contrast, conventional plate osteosynthesis requires so-called friction between the plate and the bone in order to fix the fracture.

Conical threaded joints nevertheless have the advantage that the threads dig into each other when tightened tightly. This bite reduces the risk of the rigid plate/threaded joint loosening unintentionally due to cyclic loads.

[0012] This rigid plate/threaded joint is, for example, WO88
This can also be achieved with a screw with an inflatable head as disclosed in US Pat.

[0013] The iron-like shape of the plate is preferably realized in such a way that the underside of the plate, including the tip of the plate, forms a straight line. On the other hand, the upper surface of the plate extends downward in a curved manner toward the tip. Preferably the side plate walls should also taper slightly towards the tips. This shape allows the plate to automatically approach the bone when slid forward, ie the plate can be slid forward along the bone while being inspected.

As an alternative, the lower surface of the plate may be slightly curved like the upper surface. The tip of the sled is in this embodiment on the central axis of the plate. The tip of the plate configured in this way can penetrate soft tissue without cutting, but since the soft tissue along the path is uniformly removed upward and downward, it does not tend to follow only the bone surface. not present. This embodiment is therefore originally suitable for cases in which a channel has to be created for the introduction of the plate (arthroscopically) and makes it possible to install the locking screw very close to the tip of the plate, but this is not possible in the case of a sliding tree tip.

The advantages achieved by the invention are essentially as follows.

- The osteosynthesis plate can be used as a bridging plate and the fracture does not have to be 100% reduced.

- The osteosynthesis plate may not be adapted to the anatomy of the bone to be treated.

- The graft is carried out through a very small incision far away from the fracture. Additional disturbance of the biology around the fracture site is thereby minimized. The cosmetic benefits of multiple short scars are significant.

- The iron-like plate can be easily made by using the guide grip.
It will be introduced while being inspected.

- Drilling, thread cutting, length measurement and screw installation can be suitably carried out by means of a guide handle.

- The fixation of the screw heads in the holes of the plate allows the plate to protrude from the bone surface, which is extremely important for maintaining blood circulation in the bone. - Since screw fixation is required only in the mesocortex, the number of screw types can be reduced to about three screw types per system size.

- The screws used in the monocortex can have self-tapping screws since they reach into the medullary canal. The tip of the screw being cut does not endanger the soft parts.

[0023]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention, which also explains the functional principle, is shown in the drawings and will be described in detail below.

FIG. 1 is a longitudinal sectional view of an osteosynthesis plate according to the present invention and an introduction and aiming device fixed thereto.

The osteosynthesis plate 10 shown in FIG. 1 has substantially an upper surface 1, a lower surface 2, a plurality of holes 3 for receiving bone screws 30 and connecting the upper surface 1 and the lower surface 2, and two plate ends. 5 and 7. One end 5 of the board has an inclined surface 6 on the upper side 1 of the board 10, similar to the tip of an iron, so that when introducing the board 10 into the soft part, as little resistance as possible is encountered and therefore the least damage occurs. For this purpose, the side wall 9 of the plate can also be slightly tapered towards the tip. The other plate end 7 has a cylindrical screw hole 8 as a connecting means, into which an introduction and aiming device 20 can be removably fixed by means of a mounting screw 21. The bore 3 is configured as a cone tapering towards the lower surface 2 with an internal thread 33, which corresponds to the external thread 32 of the receiving bone screw 30. This brings about the crucial point that plate 10 and screw 3
An absolutely rigid connection can be achieved with 0. The cone angle is conveniently between 2.0° and 4.0°, preferably between 2.5° and 3.5°, particularly preferably between 3°. The hole 3 is formed in such a way that the head 31 of the bone screw 30 to be received can be rigidly connected to the plate 10. The bore 3 is formed as a cone tapering towards the lower surface 2 and has a thread 33 corresponding to the external thread 32 of the conical head 31 of the bone screw 30 which it preferably receives.

The iron-like introducing and aiming device 20 has a cylindrical hole 27 at the end 22 adapted to be connected to the plate 10, into which a mounting screw 21 is inserted and the introducing and aiming device 20 is inserted.
can be temporarily fixed to the plate 10. This end 2
A spacer element 23 arranged at right angles following 2 has an actual guide grip 24 extending parallel to plate 10. A cylindrical hole 25 is provided in the guide handle 24 of the introduction and aiming device 20, the axis 26 of which coincides exactly with the axis 4 of the hole 3 in the plate. This allows the coaxial screw 30 to be inserted through the hole 25 using a suitable instrument 40 (boring machine, length measurer, installation tool, etc.).
It becomes possible to quickly and accurately fix the plate 10 within the bone without requiring an X-ray device. The coupling and uncoupling of the introduction and aiming device 20 by means of the mounting screw 21 also takes place through the corresponding hole 25 in the guide handle 24, which is aligned with the hole 8 in the plate 10.

The dimensions of the plate 10 are largely determined by the bone to be fixed or the fracture to be treated. When applied to the tibia, the plate width is approximately 12 mm, the plate height is approximately 4 mm, and the plate length is 20 mm.
It is 0 to 300 mm. These dimensions will be somewhat larger for femoral applications.

The spacer member 23 has a length of approximately 50 mm when applied to the tibia, and approximately 100 mm when applied to the femur.

FIG. 2 is a longitudinal sectional view of the osteosynthesis plate according to the present invention implanted in the tibia and the introducing and aiming device fixed thereto.

FIG. 2 shows the state of the plate 10 implanted in this way for bridging the fracture 51 of the tibia 50.
An introduction and aiming device 20 is still attached to this plate and projects outwardly through the cutout 52. The plate 10 is fixed to the bone with three screws 30 disposed distal and proximal from the bone fracture 51.
The gap 53 remaining between the plate 10 and the plate 10 enables defect reproduction.

FIG. 3 is a plan view of the osteosynthesis plate applied to the femur, with the introducing and aiming device already removed.

FIG. 3 shows a plate 10 similarly implanted to bridge a fracture 61 of a femur 60. The introducing and aiming device used for this purpose (not shown) has here already been removed through the incision 62. Similar to that shown in FIG. 2, in this surgical technique the individual bone fragments 61 are not fixed as such but are bridged by plates 10.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an osteosynthesis plate according to the present invention and an introduction and aiming device fixed thereto.

FIG. 2 is a longitudinal sectional view of the osteosynthesis plate according to the present invention implanted in the tibia and the introduction and aiming device fixed thereto.

FIG. 3 is a plan view of the osteosynthesis plate applied to the femur, with the introduction and aiming device already removed.

[Explanation of symbols]

1: Upper surface, 2: Lower surface, 3: Hole, 5, 7: Plate end, 6: Inclined surface, 8: Screw hole, 9: Side wall, 10: Bone joint plate, 20: Introduction and aiming device, 21: Mounting screw , 23: Spacer member, 24
: Guide grip, 25, 27: Cylindrical hole, 26: Axis, 3
0: bone screw, 32: male screw, 33: female screw, 50:
Tibia, 51, 61: Fracture, 52, 62: Incision, 53
: void, 60: femur.

Claims (10)

[Claims] 1. An upper surface (1), a lower surface (2), a plurality of holes (3) for receiving bone screws (30) and communicating the upper surface (1) and the lower surface (2), and two plates. In an osteosynthesis plate (10) having ends (5, 7) and two lateral plate walls (9), one plate end (5) is a free end and the other plate end (7) is an introductory plate end. An osteosynthesis plate characterized in that it has coupling means, preferably screw holes (8), for removably coupling with a combination aiming device (20). 2. The osteosynthesis plate according to claim 1, characterized in that the free end of the plate end (5) has a tapered part mainly as an inclined surface (6) of the upper surface (1). 3. The lateral plate wall (9) is tapered at the free end of the plate end (5), preferably forming a cutting edge or a point. osteosynthesis plate. 4. The osteosynthesis plate according to claim 2 or 3, wherein the lower surface (2) has an inclined surface at the free portion of the plate end (5). Claim 5: The head (3) of the bone screw (30) to be received.
5. Osteosynthesis plate according to claim 1, characterized in that the holes (3) are formed so that the plate (10) can be rigidly connected to the plate (10). 6. The hole (3) is formed as a cone tapering towards the lower surface (2), which preferably accommodates the external thread of the conical head (31) of the bone screw (30). 6. The osteosynthesis plate according to claim 5, characterized in that it has threads (33) corresponding to (32). [Claim 7] The cone angle of the hole (3) is 2.0° to 4.0°.
7. The osteosynthesis plate according to claim 6, characterized in that the angle is preferably 2.5° to 3.5°. 8. An introduction and aiming device (20) for use with an osteosynthesis plate according to any one of claims 1 to 7, characterized in that it is arranged in a guide grip (24) and in a guide grip (24). Introducing and aiming device characterized in that it has a spacer member (23), and an end (22) following the spacer member (23) and adapted to be connected to the plate (10). 9. The end (22) adapted to be connected to the plate (10) has a cylindrical shape as a connecting means for fixing the introducing and aiming device (20) to the plate (10) in a removable manner. Introducing and aiming device (20) according to claim 8, characterized in that it has a hole (27). 10. Characterized in that the guide grip (24) is provided with a preferably cylindrical hole (25), the axis (26) of which coincides exactly with the axis (4) of the hole (3) in the plate. Introducing and aiming device (20) according to claim 8 or 9.